The invention relates to a smoothing device of a coating applying unit for coating a moving web. More particularly, the invention relates to deflection compensation apparatus for the support beam of the smoothing device for a web coating unit. The smoothing device supports a doctor element and includes means which maintain the doctor element at the desired pressure against the web or against a counter roller arranged counter to the doctor element and on which the web moves. The beam is likely to sag under the combined effects of gravity and to a lesser extent to counter the effect of the pressure on the doctor supported on the beam.
The smoothing device comprises a support beam which supports the doctor element via a holding means on the support beam. A central support member extends through the typically hollow support beam. At least two rows of hydraulically or pneumatically actuated, i.e. pressure fluid or pressure medium actuated, pressing elements extend longitudinally along the smoothing device and are disposed between the central support member and the support beam. The invention concerns the manner in which the pressing elements are connected with and act upon the support beam.
Such a device has been proposed in British Patent No. 1,202,167. There the support beam is hollow in order to increase the rigidity of the support beam in relation to its weight.